Interurban / 54 metros / Philadelphia
Philadelphia
A pre-war city with a subway, an elevated, trolleys and regional rail already in place. The bones are extraordinary and the money never is.
- Residents
- 3,683,718Census 2020, observed
- Census tracts
- 926TIGERweb, 2020 vintage
- Counties
- Philadelphia, Delaware, Montgomery, BucksWhat the pack covers
- Existing rail
- NoneNo published rail feed
- Difficulty
- ForgivingNortheast
What you are given
Every one of Philadelphia's 926 census tracts arrives with its real numbers attached: resident population, population 18 and over, occupied households, jobs by sector at the workplace, resident workers, and median household income — each one hoverable, each one carrying its GEOID so you can go and check it against the Census yourself.
Work trips are not guessed. They are seeded from the observed LEHD LODES home-to-work flows between those tracts, so the real spatial structure of the region — a century of geography, zoning and history that no gravity model reproduces — is preserved, and the model predicts only the change your network causes.
Philadelphia has no rail transit in the pack, because its agency publishes no rail feed. You are starting from nothing but bus, and the map will tell you honestly that there is nothing there.
What makes Philadelphia hard
Forgiving. Dense, centred, and already used to transit — the model has something to work with on day one. There is no network to inherit and no habit of using one, which the mode choice model expresses as a constant working against you before you have drawn anything.
And the decade changes the problem, not the vehicle list. Philadelphia in 1960 is a different city from Philadelphia in 2025: smaller, denser, fewer cars per household, no federal transit money at all, and an expectation that you cover your own operating cost. The population distribution is back-cast by pivoting the real 2020 distribution rather than invented, so the rivers and the rail yards and the university stay where they are.
Philadelphia is in the free game. One of thirteen metros you can play without paying anything — the whole demand model, the operating budget, the events, the strike, the land use and the full progression ladder, on rail, in 2025, for ten years. Not a cut-down demo: the same simulation.
Where these numbers come from
- Population, households, population 18+ — Census 2020 PL94-171, tables P1, P3 and H1. Observed.
- Median household income — ACS 2018–2022 5-year, table B19013. Where the Census suppresses a tract, the pack records it as unknown and never estimates one.
- Jobs and commute flows — LEHD LODES8 2022, WAC, RAC and OD (JT00, S000). Observed.
- Tract geometry, water, roads — Census TIGERweb, 2020 tract vintage.
- Traffic counts — FHWA HPMS, functional class 1–4, as reported by the state DOT; each pack's own source string names the vintage its state publishes.
The full model specification, with every coefficient and its source →